Ionizing radiation creates a risk of injury to persons exposed to such energy. Such radiation can be natural or generated and numerous sources can be encountered in medicine industry, research and academic work. As an example, ionizing radiation is often generated by various types of equipment, such as x-ray machinery, used in the medical or dental profession. Accordingly, there is a heightened risk of exposure to persons who work in this discipline. To avoid prolonged, or over-exposure to radiation, as well as to comply with federal regulations, the exposure to radiation of involved medical professionals is generally closely monitored.
Two groups of devices are most commonly used to measure exposure to radiation. The first type of device consists of a meter that detects and quantifies the level or intensity of radioactivity. These devices make instantaneous measurements and do not typically provide information regarding accumulation of exposure. The second group of devices measures the accumulated amount of radiation a person has been exposed to over a given period of time, and are referred to by those skilled in the pertinent art as dosimeters.
Dosimeters provide information on accumulated radiation exposure by integrating the various different, and often variable intensity doses of radiation to which a person is exposed over a given period of time. The duration of data collection can vary from minutes to weeks depending on exposure conditions and surveillance requirements. Usually, the dosimeter is in the form of a badge that can be clipped onto a person's clothing.
Dosimeters can include real time devices, i.e., the self reading gauge dosimeters (SRD); and those requiring processing: film radiation detectors; and thermoluminescent dosimetry (TLD), utilizing lithium fluoride (LiF) chips. The TLD is the most robust, reliable and accurate means of dose estimation.
Usually, a dosimeter is worn in proximity to the chest or waist, and is clipped onto clothing or suspended from a chain. Dosimeters can also be attached to the extremities or other locations on the body to provide more accurate data appropriate to a specific exposure situation. However, difficulties sometimes arise as a result of a person forgetting to attach the dosimeter, or as a result of inappropriate placement of the dosimeter when localized exposure occurs. This can result in undetected overexposure, that in turn could injure the unsuspecting individual. This problem is most frequently encountered when a person's face and eyes are exposed to a discrete beam of radiation, and the dosimeter is positioned below the person's neck.
Based on the foregoing, it is the general object of the present invention to provide a radiation measurement device that overcomes the problems and drawbacks associated with prior art devices.
It is a more specific object of the present invention to provide a device capable of accurately measuring the level of exposure to radiation of the facial area of an individual.